fix: 修复前台4项问题(MCP列举/微信技能上限/Word资产栏/技能MCP反馈) + 同步容器live状态

- #549 平台MCP列举: 注入全量已启用MCP清单, AI不再凭空编造
- #550 微信Bot技能自动发现上限 15->300
- #551 知识库Word文档同步资产后Word栏可见 + 双向删除同步(assets/knowledge级联软删)
- #552 对话反馈实际使用的技能/MCP(used_mcp字段), 含历史消息序列化
- 同步容器内其他未提交live改动(im_bot_platform/TokenDashboard/WechatBot/ChatPage)

backend/python/app/api/assets.py

@@ -368,6 +368,19 @@ def delete_asset(
     asset.status = "deleted"
     asset.updated_at = datetime.now()
 
+    # 若资产由知识库文档同步而来，双向删除对应的知识库文档
+    if asset.knowledge_doc_id:
+        try:
+            kb_doc = db.query(KnowledgeDocument).filter(KnowledgeDocument.id == asset.knowledge_doc_id).first()
+            if kb_doc:
+                kb = db.query(KnowledgeBase).filter(KnowledgeBase.id == kb_doc.knowledge_base_id).first()
+                if kb:
+                    kb.document_count = max(0, (kb.document_count or 0) - 1)
+                    kb.updated_at = datetime.now()
+                db.delete(kb_doc)
+        except Exception:
+            pass
+
     LogService.log_operation(
         user_id=current_user.id, username=current_user.username, action="delete",
         target="asset", target_id=asset.id,